public class CargoBoat {
    int realContent;
    int maxContent;
    public void setMaxContent(int c){
        maxContent = c;
    }
    public void loading(int m)throws DangerException{
        realContent += m;
        if(realContent>maxContent){
            realContent -= m;
            throw new DangerException();
        }
        System.out.println("目前装载了"+realContent+"吨货物");
    }
}

